Correlation between degenerative spine disease and bone marrow density: a retrospective investigation

Background: Spondylosis leads to an overestimation of bone mineral density (BMD) with dual-energy x-ray absorptiometry (DXA) but not with quantitative computed tomography (QCT). The correlation between degenerative changes of the spine and QCT-BMD was therefore investigated for the first time. Methods: One hundred thirty-four patients (66 female and 68 male) with a mean age of 49.0 +/- 14.6 years (range: 19-88 years) who received a CT scan and QCT-BMD measurements of spine and hip were evaluated retrospectively. The occurrence and severity of spondylosis, osteochondrosis, and spondylarthrosis and the height of the vertebral bodies were assessed. Results: A negative correlation was found between spinal BMD and number of spondylophytes (rho = -0.35; p < 0.01), disc heights (r = -0.33; p < 0.01), number of discal air inclusions (rho = -0.34; p < 0.01), the number of Schmorl nodules (rho = -0.25; p < 0.01), the number (rho = -0.219; p < 0.05) and the degree (rho = -0.220; p < 0.05) of spondylarthrosis. Spinal and hip BMD correlated moderately, but the latter did not correlate with degenerative changes of the spine. In linear regression models age, osteochondrosis and spondylarthrosis were factors influencing spinal BMD. Conclusion: Degenerative spinal changes may be associated with reduced regional spinal mineralization. This knowledge could lead to a modification of treatment of degenerative spine disease with early treatment of osteopenia to prevent secondary fractures.